Vlad Guerrero Jr. and MLB's Top Breakout Candidates at Every Position in 2019

Toronto Blue Jays superstar prospect Vladimir Guerrero Jr. is a popular pick as he gets set to take the league by storm, but he's not the only player positioned to join the ranks of the game's elite.

Ahead, we've highlighted three breakout candidates at each position, along with naming a few others worth keeping an eye on.

Whether it's a promising sign in a player's peripheral numbers, a lengthy track record of success at the minor league level or a simple hunch, each of the following players appears ready to take a step forward.

It's important to realize that this is as much about opportunity as upside.

Is Garrett Hampson going to have a better career than Keston Hiura? Probably not, but there's a good chance he'll make a bigger impact in 2019 thanks to a more clear path to playing time.

With that in mind, let's get started.

Catchers

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Danny JansenTom Szczerbowski/Getty Images

Danny Jansen, Toronto Blue Jays

The salary dump of veteran catcher Russell Martin opens the door for Jansen to seize the starting catching job this spring. He hit .275/.390/.473 with 21 doubles and 12 home runs in 88 games at Triple-A last season and then posted a 115 OPS+ with six doubles and three home runs in a 31-game audition.

The 23-year-old has a chance to immediately be one of the better offensive catchers in baseball.

Jorge Alfaro, Miami Marlins

Alfaro finished last season on a tear, hitting .367/.472/.567 over 13 games in September. Now, he moves to a low-pressure environment in Miami where he'll be given every chance to succeed as a presumptive long-term piece of the rebuilding puzzle.

There's a lot to like about the 25-year-old's upside. He has a solid hit tool, 20-homer power and a rocket arm behind the plate.

Grayson Greiner, Detroit Tigers

In his last full season in the minors in 2017, Greiner posted a .746 OPS with 21 doubles and 14 home runs while throwing out 37 percent of base-stealers. The rebuilding Tigers are hoping those skills will translate with an extended look in the majors.

"Greiner's going to be the guy," manager Ron Gardenhire told Jason Beck of MLB.com. "We think he can handle it. He did some pretty good things last year. It's his turn. We've got to see what happens and we'll go from there."

First Basemen

"I just wanna force someone's hand," Alonso told reporters of his impending battle for the first base job with veteran Todd Frazier this spring.

Even if he doesn't break camp with the team, it won't be long before Alonso is penciled into the middle of the Mets lineup. The 24-year-old hit .285/.395/.579 with 31 doubles, 36 home runs and 119 RBI between Double-A and Triple-A last season and then posted an .849 OPS with seven doubles and six home runs in 27 games in the Arizona Fall League. He's ready.

Luke Voit, New York Yankees

After coming over from the St. Louis Cardinals in an under-the-radar deadline deal, Voit hit .333/.405/.689 with 14 home runs in 148 plate appearances in pinstripes. Those numbers won't be sustainable over a full season, but even a watered-down version of that would be more than welcome.

Something like a .260/.330/.455 line with 25 home runs and 75 RBI is probably more realistic, and that would still represent an upgrade over what the first base position has produced the past few seasons.

Nate Lowe, Tampa Bay Rays

Ji-Man Choi and Yandy Diaz will enter camp as the Rays' leading candidates for playing time at first base, and both players offer some intriguing, low-cost offensive upside. That said, they might simply be keeping the position warm for Lowe.

A 13th-round pick in 2016, Lowe jumped onto the fast-track last season thanks to a .330/.416/.568 line that included 32 doubles, 27 home runs and 102 RBI over three minor league levels, culminating in 28 games at Triple-A Durham. His ascension was likely a big reason why the team was willing to trade Jake Bauers.

Second Basemen

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Luis UriasDenis Poroy/Getty Images

Luis Urias, San Diego Padres

Even with the signings of Manny Machado and Ian Kinsler, Urias looks like a safe bet to see regular playing time during the 2019 season. The most likely solution would be to play Machado at shortstop and Kinsler at third base until Fernando Tatis Jr. gets called up, at which point Machado would slide over to the hot corner and Kinsler would move into a utility role.

The 21-year-old Urias is a .306/.397/.405 hitter over five minor league seasons and has almost as many walks (220) as he does strikeouts (244) in 2,062 plate appearances. That should make him a dynamic top-of-the-order table-setter, and with the glove to stick at shortstop if not for Tatis, he'll also be an asset on defense.

Garrett Hampson, Colorado Rockies

There will be a lot of moving parts on the right side of the Colorado infield with the return of Mark Reynolds and both Daniel Murphy and Ryan McMahon capable of playing first and second base.

Still, Hampson should have a chance to play his way into the starting second base job. The 24-year-old hit .315/.389/.457 and racked up 123 steals in three minor league seasons, and he has the requisite tools to develop into a Gold Glove-caliber replacement for DJ LeMahieu.

Kevin Kramer, Pittsburgh Pirates

While Adam Frazier will likely break camp as the starting second baseman, the Pirates may ultimately prefer him in the super-utility role he filled last season. That would open the door for Kramer.

The 25-year-old enjoyed a breakout season at Triple-A with a .315/.365/.492 line that included 35 doubles, 15 home runs and 13 steals. There are several other in-house options, but it's Kramer who could solidify himself as the long-term answer at second base before the 2019 season comes to a close.

Shortstops

Adames made his long-awaited MLB debut on May 22, but he was hitting just .200/.256/.296 with five extra-base hits in 125 plate appearances at the end of July. Despite those early struggles, the Rays stuck with him, and that patience paid off in a big way over the final two months.

The 23-year-old went on to hit .329/.406/.480 with five doubles, seven home runs and 25 RBI in 198 plate appearances over his final 51 games. That might be just the tip of the iceberg for a player who has always had star potential.

Fernando Tatis Jr., San Diego Padres

Had a fractured thumb not abruptly ended Tatis' season last July, he might have already made his MLB debut. Then again, with service-time considerations in play, who knows?

At any rate, the 20-year-old has all the makings of a future superstar. After hitting .286/.355/.507 with 22 doubles, 16 home runs and 16 steals at Double-A prior to the thumb injury, he has little left to prove in the minors, and the Machado signing shows the Padres are serious about contending.

If he's up before the All-Star break, he'll be squarely in the NL Rookie of the Year conversation.

Adalberto Mondesi, Kansas City Royals

The hype train has already left the station on Mondesi after he posted an .886 OPS with five doubles, eight home runs and 14 steals in 26 games in September.

All told, he wrapped up his first full season in the majors with a .276/.306/.498 line, slugging 13 doubles and 14 home runs while also swiping 32 bases in 39 attempts. There's 20-homer, 50-steal potential here, to go along with Gold Glove-caliber defense at shortstop as he enters his age-23 season.

Others to Watch: Erik Gonzalez (PIT), Jorge Polanco (MIN)

Third Basemen

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Vladimir Guerrero Jr.Christian Petersen/Getty Images

Vladimir Guerrero Jr., Toronto Blue Jays

The notoriously conservative Steamer projections have pegged Vlad Jr. for a .306/.368/.511 line with 30 doubles, 22 home runs and 78 RBI, to go along with a 4.7 WAR that ranks 13th among all position players.

That might be his floor.

Simply put, the 19-year-old is a generational talent. The fact he's going to start the 2019 season in Triple-A is further proof of how hopelessly broken the current arbitration system is and could be the final straw that leads to a much-needed overhaul.

Rafael Devers, Boston Red Sox

There's not anything in Devers' peripheral numbers to suggest bigger and better things are coming. Instead, it's his age and minor league track record that lend optimism for a potential step forward.

Despite having 179 MLB games under his belt, he'll still be just 22 years old for the entire 2019 season. With a .297/.354/.484 line over five minor league seasons, he's capable of more than his disappointing .240/.298/.433 showing last year. His plus raw power also makes him a clear 30-homer threat.

It's only a matter of time.

Maikel Franco, Philadelphia Phillies

Franco showed what he's capable of when everything is clicking last July, hitting .330/.378/.593 with seven home runs and 15 RBI in 98 plate appearances.

This looks like a make-or-break season for the 26-year-old former top prospect, and as the Phillies look to be a factor in the NL East, he's among the biggest X-factors on the roster.

Outfielders

Dahl returned to the Colorado lineup on Aug. 5 after missing 54 games with a broken foot, and his red-hot finish helped propel the Rockies to a wild-card berth.

The 24-year-old posted a .985 OPS in September with nine home runs and 27 RBI in 24 games.

Health is always the big question mark with Dahl. If he can stay healthy, he'll join Nolan Arenado, Trevor Story and Charlie Blackmon in leading a potent offensive attack.

Eloy Jimenez, Chicago White Sox

With an imposing 6'4", 205-pound frame and 70-grade power, Jimenez has some of the best pop in all of baseball. He's more than just an all-or-nothing slugger, though.

The 22-year-old was also given a 65-grade hit tool, and after batting .337/.384/.577 between Double-A and Triple-A, it's not hard to envision a Manny Ramirez-type middle-of-the-order slugger.

Service-time considerations will mean a ticket to Triple-A to start the year, but he'll be manning left field and hitting in the middle of the White Sox order before the All-Star break. If anyone is going to upset Vlad Jr. for AL Rookie of the Year honors, he's the best bet.

Victor Robles, Washington Nationals

Unless the Nationals find a way to re-sign Bryce Harper, there's a clear path to playing time for Robles.

The 21-year-old profiles more as a table-setter at this point in his career, with 75-grade speed and an advanced approach that makes him a consistent on-base threat. There could be 20-plus home run power down the road, but even if that never comes, he looks like a dynamic two-way center fielder.

Starting Pitchers

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Walker BuehlerPool/Getty Images

Walker Buehler, Los Angeles Dodgers

There's a good chance we haven't seen the best Buehler has to offer. That's a scary thought for hitters around the league, considering how dominant he was down the stretch last season in the heat of a pennant race.

The 24-year-old posted a 1.62 ERA, 0.77 WHIP and a .137 opponents' batting average with 45 strikeouts in 39 innings over the final month of the season. That was capped off by 6.2 scoreless innings of one-hit ball in the decisive Game 163 to clinch the NL West title.

It was Kyle Freeland who finished fourth in NL Cy Young voting and was hailed as a breakout star in 2018. It's Marquez who had better peripheral numbers across the board, though, and he's the better bet to lead the staff going forward.

Shane Bieber, Cleveland Indians

On the surface, Bieber had a ho-hum rookie season, posting a 96 ERA+ with a 4.55 ERA and 1.33 WHIP over 114.2 innings.

However, his 3.23 FIP and an absurdly high .356 BABIP speak to a pitcher who's headed for some significant positive regression. Throw in a 5.1 strikeout-to-walk ratio that ranked 10th among all pitchers who threw at least 100 innings, and it's hard not to get excited about what's to come.

Relief Pitchers

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A.J. MinterScott Cunningham/Getty Images

A.J. Minter, Atlanta Braves

Very few lefties throw harder than Minter, who averaged 97.1 mph with his fastball. He complements that heat with a wipeout slider that held opposing hitters to a .065 ISO and generated a 21.5 percent whiff rate.

The 25-year-old spent part of last season in the closer's role while Arodys Vizcaino was hurt, nailing down 15 saves in 17 chances while posting a 3.23 ERA and 10.1 K/9 in 65 appearances. He could win the ninth-inning job outright this spring, but even if he returns to a setup role, he's already on his way to becoming a bullpen star.

Matt Barnes, Boston Red Sox

Unless the Red Sox change course and re-sign Craig Kimbrel, it looks like the closer job in Boston will go to either Barnes or standout rookie Ryan Brasier.

The 28-year-old Barnes turned in a dominant 2018 season, raising his strikeout rate from 28.9 to 36.2 percent on his way to 14.0 K/9 while tallying a team-high 25 holds. A smooth transition into the ninth-inning role would erase perhaps the biggest question mark surrounding the Red Sox.

Bobby Wahl, Milwaukee Brewers

The Brewers acquired Wahl in the deal that sent outfielder Keon Broxton to the Mets, and he could make an immediate impact in an already stacked bullpen.

The 26-year-old has yet to find success at the MLB level in limited action, but he's been absolutely dominant in the minors. In 38 appearances at Triple-A last season, he posted a 2.20 ERA and 0.87 WHIP with 12 saves and an eye-popping 73 strikeouts in 45 innings.

"This has a shot to be a really good deal for Milwaukee," one scout toldRobert Murrayof The Athletic, referring to the addition of Wahl.